1. Field of the Invention
The present invention relates to a terminal for connecting an electric wire to a connecting terminal of an electrical component such as a bus bar, a relay or a fuse.
2. Description of Related Art
A terminal 101, as shown in Japanese Patent Publication No. 2007-250362, has been used, for example, for a connection between an electric wire and a connecting terminal of an electrical component such as a bus bar, a relay or a fuse. The terminal 101 shown in FIG. 6 includes an electrical contact portion 103 and an electrical connecting portion 105. A plate-like insert portion 110a of a mating terminal 110 is inserted into the electrical contact portion 103, so that the electric wire is electrically connected to the connecting terminal of the electrical component such as the bus bar, the relay or the fuse.
The terminal 101 made of electrically conductive flat-plate-shaped sheet metal is formed into L-shape, and is provided with the electrical contact portion 103 at one end thereof and the electrical connecting portion 105 at the other end thereof.
The electrical connecting portion 105 is provided with a hole 105a which is to be connected with the electrical component such as the bus bar, the relay or the fuse.
The electrical contact portion 103 is formed into a tube shape with a bottom wall 103a, an upper wall 103c opposing to the bottom wall 103a, and a pair of side walls 103b continuing to both the bottom wall 103a and the upper wall 103c. The electrical contact portion 103 has a spring member 104 including three elastic pieces 104a and connecting pieces 104b. The three elastic pieces 104a and the connecting pieces 104b are formed integrally by punching out a flat-plate-shaped metal sheet. The spring member 104 is provided at the bottom wall 103a of the electrical contact portion 103.
Each of the three elastic pieces 104a is flexible and has a rectangular shape. The three elastic pieces 104a are arranged in parallel to each other, at an interval, along a direction perpendicular to z-direction, so that longitudinal direction thereof is parallel to the z-direction. One end of each elastic piece 104a in a widthwise direction thereof is arranged to be contacted with the bottom wall 103a. The each elastic piece 104a is formed to slant the other end thereof in the widthwise direction thereof toward the upper wall 103c. 
The connecting pieces 104b are formed into a plate-like shape and are provided in pairs. The pair of connecting pieces 104b is provided on both ends of the bottom wall 103a in a longitudinal direction thereof with a space between each other, so that the longitudinal direction thereof is perpendicular to the z-direction. Three elastic pieces 104a are positioned between the connecting pieces 104b, so that both ends in a longitudinal direction thereof are continuous with the connecting pieces 104b. Longitudinal length of each connecting piece 104b is substantially same as the width of an inner surface of the bottom wall 103a. 
For the conventional terminal 101 described above, the insert portion 110a of the mating terminal 110 is inserted in between the bottom wall 103a and the upper wall 103c, and in between the side walls 103b. The inserted insert portion 110a is then sandwiched and held by the elastic pieces 104a and the upper wall 103c. The elastic pieces 104a push the insert portion 110a towards the upper wall 103c. 
In the manner described above, the terminal 101 connects the electric wire to the connecting terminal of the electrical component such as the bus bar, the relay or the fuse.
However, according to the conventional terminal 101, when the insert portion 110a of the mating terminal 110 enters into the electrical contact portion 103, the three elastic pieces 104a, arranged in parallel to each other in direction substantially perpendicular to the z-direction, are pushed against the bottom wall 103a, and deformed elastically. An elastic restoring force by the deformed three elastic pieces 104a is simultaneously generated, pushing the insert portion 110a against the upper wall 103c. Thus a large force (insertion force) is required in order to insert the insert portion 110a into the electrical contact portion 103.
Thus, for example when inspecting the terminal 101, the required large force to insert the insert portion 110a into the electrical contact portion 103 causes a heavy workload for a worker. Furthermore, there was a need for applying grease to reduce the insertion force to lighten the workload, increasing a number of working process.
Furthermore, since the longitudinal direction of the elastic pieces 104a is arranged in parallel to the z-direction, when the insert portion 110a enters into the electrical contact portion 103, the ends on one side of the elastic pieces 104a in the longitudinal direction thereof, and a top end of the insert portion 110a will contact intersectionally. Thus, the insert portion 110a pushes the ends of the elastic pieces 104a, causing the spring member 104 to be detached easily from the electrical contact portion 103.
Furthermore, the pair of the connecting pieces 104b is provided at ends of the bottom wall 103a, so that the longitudinal direction thereof is arranged perpendicular to the z-direction. Thus, when the insert portion 110a enters into the electrical contact portion 103, the top end of the insert portion 110a pushes the connecting piece 104b1 causing the spring member 104 to be detached easily from the electrical contact portion 103.
In view of the above-described problems, an object of the present invention is to provide a terminal which can reduce a large insertion force generated when inserting an insert portion of a mating terminal into an electrical contact portion of the terminal, and which can also reduce a failure rate by preventing a spring member to be detached easily when inserting/pulling out the insert portion of the mating terminal into/from the electrical contact portion of the terminal.